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David Berry -11- June 20, 1996 47. An annotation of culvert C-F1 was added to Map 20, Sedimentation Control Plan. Enclosed is revised Map 20. 48. The DMG's comments about its general guidelines for erosive velocities is noted. 49. Annotations for culverts D-F1 and D-F2 were added to Map 20, Sedimentation Control Plan. Enclosed is revised Map 20. 50. The data for ditches D-D1, D-D2, D-E1, D-F1 and D-F2 was added to the V-Ditch Design table found on enclosed page Exh-8-24. 51. The operator has requested, on page 12 of section 4.1.5 of Volume IV, small area exemption status for the coal waste pile topsoil stockpile and the coverfill stockpile. However, no designs have been submitted, pursuant to Rule 4.05.2(3). Please submit such designs, after which the Division can determine whether small area exemption status is appropriate. In the designs, please account for the fact that the two areas seem to be placed at the bottom of drainage watersheds, which could result in significant erosion due to runoff from a storm event. WESTEC has incorporated systems into the design to control runoff above and off of the coverfill and topsoil stockpiles. The topsoil stockpile is protected from uphill overland runoff by the ditch along the haul road to the waste bank. The topsoil stockpile will be seeded contemporaneous with construction, and will have alternative sediment control structures such as silt fences or straw bales at the slope toe to control any sediment that may accumulate. BRL will commit to frequent monitoring of the alternative sediment control structures and upkeep, as necessary. At the coverfill stockpile, the structure is located between two hills, but signs of concentrated flows (i.e., stream erosion) between the hills were not observed in field investigations. Nonetheless, an upland diversion ditch was incorporated topographically above the coverfill stockpile for overland flow protection produced by a 10-year, 24-hour storm event. At the coverfill stockpile haul road, a 10 percent haul road ditch was incorporated for runoff control on the west side of the coverfill stockpile. Alternative sediment control structures such as silt fences or straw bales will be incorporated at the toe of the coverfill stockpile to control runoff from the slope of the stockpile. in addition to the above matters which are intended to meet the effluent limitations of 4.05.2, BRL's request is based on several additional factors. First, the coverfill and topsoil stockpiles encompass very limited areas. Second, WESTEC considered various options in an attempt to locate all